RIO DE JANEIRO – Rio de Janeiro is mixing technology with tradition to provide tourists information about the city by embedding bar codes into the black and white mosaic sidewalks that are a symbol of the city.

The first two-dimensional bar codes, or QR codes, as they’re known, were installed Friday at Arpoador, a massive boulder that rises at the end of Ipanema beach. The image was built into the sidewalk with the same black and white stones that decorate sidewalks around town with mosaics of waves, fish and abstract images.

The launch attracted onlookers, who downloaded an application to their smartphones or tablets and photographed the icon. The app read the code and they were then taken to a website that gave them information in Portuguese, Spanish or English, and a map of the area.

They learned, for example, that Arpoador gets big waves, making it a hot spot for surfing and giving the 500-meter beach nearby the name of “Praia do Diabo,” or Devil’s Beach. They could also find out that the rock is called Arpoador because fishermen once harpooned whales off the shore.

The city plans to install 30 of these QR codes at beaches, vistas and historic sites, so Rio’s approximately 2 million foreign visitors can learn about the city as they walk around.